Wheeey! BPM's aren't an exact science, some dubstep stuff can be noted by digital bpm analysers as being in the 150-170 bpm range, same with some 'rock' or punkier stuff, when it's fairly obvious to the untrained ear that they're never that fast. If you get an innacurate reading it's easy to just half the bpm to get a more accurate reading. Same the other way round, some DnB and breaks can get analysed at BPM's of as low as 75-80, where, they sound much faster.